Disposable pouch-type packages made of two layers of flexible material for single-use of liquid products are prevalent in the present consumer product market. These packages are generally torn open or cut on an edge to form the dispensing opening. If the total amount of the contained liquid is not used, the rest of the liquid cannot be stored because the container itself cannot retain its shape and lacks closure means.
Pouch-type packages having self-closing functions are also known. Among these packages are those which comprise a dispensing valve made by face-to-face flexible material which can self-close itself to some extent when the squeezing pressure is released from the package, and thus can be used for multiple dispensing.
Conventional self-closing pouch-type packages are typically made of flexible film material which take a sachet-like or pillow-like bulging shape when filled with liquid Each flexible material consists of a liquid container portion integral with a valve portion, joined along a line of connection. Typically, the shape of the package itself is not structured. Rather, the shape of these packages results from the internal pressure from the weight of the liquid contained therein, and is deformed when force is applied to the package by manual squeezing for dispensing purposes. Such deformation is not completely satisfactory for dispensing and re-closing performance of the package. First, such pouch-type package is flabby and thus difficult to hold upon dispensing. Second, the configuration of the connection portion between the liquid container and valve can constantly change depending on the amount of liquid in the container, or the amount of pressure applied, or both, thereby changing the condition of flow of the liquid. This causes difficulty to control the flow and amount of liquid to dispense. In particular, pouch-type packages made of thin flexible material cannot direct the pressure effectively to the valve for good liquid dispensing, but rather the pressure is dispersed to the surfaces of the liquid containers. Because of the difficulty to hold the package and to control amount of liquid to dispense, these packages can require use of both hands for dispensing. Third, due to changing of the shape and angle of the connection portion between the fluid container and valve, the stream of liquid cannot be cut off sharply and quickly at the valve. Fourth, the closure of these sachet-like or pillow-like packages are not sufficiently tight such that the contained liquid gradually leaks out after the package is re-closed because of liquid pressure against the valve due to the weight of the contained fluid.
Some of these self-closing pouch-type products have elongated valves which form a narrow, curved, or bent nozzle-like spout with an elongated flow channel. However, dispensing liquid through such elongated spout requires greater squeezing force and thus it can be difficult to control the flow and amount of liquid to dispense. Once liquid is dispensed through the spout, small amount of liquid can be trapped in the flow channel along the entire length of the elongated spout. This trapped liquid contributes to a substantial surface tension along the length of the flow channel, which increases the amount of squeezing force required to re-open the valve to dispense liquid. Further, it is difficult to dispense paste-type or gel-type high viscosity liquids with these packages, because of the greater friction from the inner surface of the narrow elongated spout which significantly increases the required manual squeezing force. These spouts can only practically be used for low viscosity liquids.
Thus, there is a desire to provide a self-closing dispensing package having improved dispensing and re-closing performance over known pouch-type packages.
Squeezable rigid bottle and tube packages comprising additional closing assemblies have good dispensing and closing characters. However, these packages require various surface preparations to make the rigid structure as well as the additional closing assembly, and add to the expense of these packages. Further, when the rigidity of the package is such that the package cannot be collapsed as the contents decrease, the liquid cannot be completely dispensed and used. Particularly, when the packages are made to contain small amount of liquid, the cost of the package in proportion to the total cost of the product becomes very high, and a substantial portion of the liquid remains unused. Moreover, because of the rigidity and relatively more material used to make these rigid structures, the amount of waste made when packages are disposed are relatively larger than the pouch-type packages as mentioned above.
Thus, there is also a desire to provide a dispensing package which is made by less material than rigid structured packages and which is collapsible to allow substantially complete dispensing of the contained liquid and thereby makes less product and package material waste, but without substantially sacrificing dispensing and re-closing performance.